SHA-224 is a cryptographic hash function that was designed by the National Security Agency (NSA) and published by the National Institute of Standards and Technology (NIST) in 2004. It is part of the SHA-2 family of hash functions, which also includes SHA-256, SHA-384, and SHA-512.
The SHA-224 generator works by taking an input message of any length and producing a fixed-length output of 224 bits. It uses a similar set of mathematical operations as SHA-256, but with a shorter output length.
This makes SHA-224 more efficient for applications where a shorter hash value is needed, such as in digital signatures and key derivation functions.
Like other SHA-2 functions, SHA-224 is designed to be secure against a wide range of attacks, including collision attacks, preimage attacks, and birthday attacks. It has a larger internal state and a more complex compression function than SHA-1, which makes it more resistant to cryptographic attacks.
SHA-224 is widely used in security protocols such as Transport Layer Security (TLS), Secure Shell (SSH), and Internet Protocol Security (IPsec). It is also recommended by NIST for use in applications that require a 224-bit hash value, such as in digital signature schemes and key derivation functions.
However, it is worth noting that newer hash functions such as SHA-3 and BLAKE2 have been developed since the introduction of SHA-2 and are generally considered more secure and efficient for modern cryptographic applications.